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author | Chris Lattner <sabre@nondot.org> | 2003-11-06 19:18:49 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2003-11-06 19:18:49 +0000 |
commit | d7222ec801618a1e22285832e7101de3dbc126d0 (patch) | |
tree | 2d3e118c7bee155895d90040e3e628efe108b88a | |
parent | 6d7aad1dd57b7928c3ffde779bf958ded3145d2a (diff) | |
download | external_llvm-d7222ec801618a1e22285832e7101de3dbc126d0.zip external_llvm-d7222ec801618a1e22285832e7101de3dbc126d0.tar.gz external_llvm-d7222ec801618a1e22285832e7101de3dbc126d0.tar.bz2 |
Fix bug: PR93
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9752 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Transforms/IPO/LowerSetJmp.cpp | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/lib/Transforms/IPO/LowerSetJmp.cpp b/lib/Transforms/IPO/LowerSetJmp.cpp index 01ff046..abbc2c9 100644 --- a/lib/Transforms/IPO/LowerSetJmp.cpp +++ b/lib/Transforms/IPO/LowerSetJmp.cpp @@ -41,6 +41,7 @@ #include "llvm/Pass.h" #include "llvm/Support/CFG.h" #include "llvm/Support/InstVisitor.h" +#include "llvm/Transforms/Utils/DemoteRegToStack.h" #include "Support/DepthFirstIterator.h" #include "Support/Statistic.h" #include "Support/StringExtras.h" @@ -377,6 +378,34 @@ void LowerSetJmp::TransformSetJmpCall(CallInst* Inst) SetJmpIDMap[Func]++), 0), "", Inst); + // We are guaranteed that there are no values live across basic blocks + // (because we are "not in SSA form" yet), but there can still be values live + // in basic blocks. Because of this, splitting the setjmp block can cause + // values above the setjmp to not dominate uses which are after the setjmp + // call. For all of these occasions, we must spill the value to the stack. + // + std::set<Instruction*> InstrsAfterCall; + + // The call is probably very close to the end of the basic block, for the + // common usage pattern of: 'if (setjmp(...))', so keep track of the + // instructions after the call. + for (BasicBlock::iterator I = ++BasicBlock::iterator(Inst), E = ABlock->end(); + I != E; ++I) + InstrsAfterCall.insert(I); + + for (BasicBlock::iterator II = ABlock->begin(); + II != BasicBlock::iterator(Inst); ++II) + // Loop over all of the uses of instruction. If any of them are after the + // call, "spill" the value to the stack. + for (Value::use_iterator UI = II->use_begin(), E = II->use_end(); + UI != E; ++UI) + if (cast<Instruction>(*UI)->getParent() != ABlock || + InstrsAfterCall.count(cast<Instruction>(*UI))) { + DemoteRegToStack(*II); + break; + } + InstrsAfterCall.clear(); + // Change the setjmp call into a branch statement. We'll remove the // setjmp call in a little bit. No worries. BasicBlock* SetJmpContBlock = ABlock->splitBasicBlock(Inst); |